Turfplaner with improved gimbal

ABSTRACT

A gimbal for attaching an implement to a three-point hitch is described. The gimball includes a tow plate comprising a first side and a second side wherein the tow plate comprises lower brackets on the first side arranged to connect to lift arms of the three point hitch and an upper bracket on the first side arranged to connect to a stabilizer arm of the three point hitch. An implement plate is rotationally attached to the tow plate wherein the implement plate comprises an upper implement bracket for coupling to an upper implement arm and a lower implement bracket for coupling to a lower implement arm.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of pending U.S. patent application Ser. No. 12/816,198 filed Jun. 15, 2010 which, in turn, claims priority to abandoned U.S. Provisional Appl. No. 61/187,067 filed Jun. 15, 2009.

BACKGROUND OF THE INVENTION

The present invention is directed to a machine for smoothing a turfed area to remove undulations. More specifically, the present invention is related to a turfplaner which comprises hydraulically activated levelers and a laser level guidance system. Even more specifically, the present invention is related to an improved gimbal for attachment of an implement to a three-point hitch of a tractor with a preferred implement including a turfplaner.

There are many environments wherein a level grass surface is of utmost importance. By way of example, without limit thereto, are airplane runways, golf courses, sports fields and the like. Leveling a large area has never been an exact science. The most common technique is to utilize a box blade, also referred to as a landscaping box, which has a forward cutting blade and a rearward drag blade. The forward cutting blade gathers materials from high spots and drags the material along while riding on the rearward drag blade. The material from the high spots is deposited in the low spots thereby decreasing undulations. One disadvantage with a box blade is that the variation from gravitational planarity is mostly a function of the tractor used to pull the box blade. It is difficult to change the general contour with a box blade and doing so generally requires many passes.

A particular advantage of smooth turf is a decrease in injuries to users of the turf. This is particularly true with athletes, or horses, wherein injury can occur if uneven turf is encountered. Yet another problem with fine turf areas is weed growth. Weed killers, pre-emergent chemicals and the like have lost favor due to the perceived problems of run-off and unintended deposition.

Implements, such as a turfplaner, for use behind a tow vehicle, such as a tractor, can be mounted such that the movement is uncorrelated to the tow vehicle or it can be correlated to the tow vehicle. With a conventional three-point hitch, for example, any movement of the tractor perpendicular to the direction of travel will translate into a similar movement in the implement. With some implements this may be desirable but with many, such as a turfplaner, it is highly undesirable. There has been a long standing need for a mount which can be used with a three-point hitch which un-correlates the movement of the implement perpendicular to the direction of travel from the movement of the tractor perpendicular to the direction of travel.

Tractors, and particularly the standard three-point hitch of a tractor, are particularly desirable tow vehicles. The standard three-point hitch has the advantage of being able to vertically lift an implement by, typically, hydraulic power. Tractors are also typically available at locations where a turf planer is likely to be used which decreases the requirement that a tractor be transported to every site of operation. Unfortunately, standard three point hitches do not allow the implement to rotate on the axis of the direction of travel. This is normally a desired feature since it important in many instances to lift an implement without rotation. With some implements, such as a turf planer the implement needs to have rotational freedom relative to the tow vehicle yet the lift features associated with a three point hitch may still be desirable for transport and the like. There is currently no suitable connection between a standard three point hitch and an implement which allow for rotational freedom during operation with selective and reversible fixing, eliminating or restricting the rotation for transport. A gimbal is provided herein which provides these necessary functions.

There has been a long-standing desire for a simple way to achieve a level turf which is weed free without chemicals and without major effort and machinery.

SUMMARY OF THE INVENTION

The present invention is related to a device, and method, for leveling an area comprising turf or an area which is intended to receive turf either as seed or sod.

A particular feature of the present invention is that an area can be leveled precisely in one pass.

Yet another particular feature is that an area can be rid of weeds without the use of chemicals.

The present invention is also related to an improved gimbal for attaching an implement to a three-point hitch.

A particular feature is an improved method for attaching an implement to a three-point hitch wherein the movement of the implement is decoupled from movement perpendicular to the movement of the tow vehicle.

These and other advantages, as will be realized, are provided in a turfplaner system, preferably coupled to a tow vehicle by a gimbal, with a laser capable of emitting a planar light over an area and a device capable of being transported over the area. The device has a rotational elongated cutter and a pair of receivers for receiving the planar light wherein each receiver is a fixed vertical distance from the cutter and on separate ends of the cutter. A control mechanism moves the rotational cutter to maintain each receiver in a fixed vertical position relative to the planar light wherein, as the turfplaner is transported over the area, the cutter removes any material above a fixed distance below the planar light.

Yet another embodiment is provided in a method for leveling an area. The method includes:

providing a laser capable of emitting a planar light over an area;

providing a device capable of being transported over the area wherein the device has:

a rotational elongated cutter;

a pair of receivers for receiving the planar light wherein each receiver is a fixed vertical distance from the cutter and on separate ends of the cutter;

a control mechanism capable of moving the rotational cutter to maintain each receiver in a fixed vertical position relative to the planar light;

moving the device over the area wherein when the device is transported over the area, preferably by a tow vehicle coupled with a gimbal, wherein the cutter removes any material above a fixed distance below the planar light.

A particularly preferred embodiment is provided in a turfplaner system. The turfplaner system includes a device capable of being transported over an area, preferably by a tow vehicle comprising a gimbal. The device includes a rotational elongated cutter with a first side and a second side and a control mechanism capable of independently altering a height of the first side of the rotational cutter and the second side of the rotational cutter relative to a predetermined height over the area.

Yet another embodiment is provided in a method for leveling an area. The method includes: providing a device capable of being transported over the area wherein the device comprises a rotational elongated cutter comprising a first side and a second side and a control mechanism capable of independently altering a height of the first side of the rotational cutter and the second side of the rotational cutter relative to a predetermined height over the area; and moving the device over the area wherein when the device is transported over the area, preferably by a tow vehicle coupled with a gimbal, wherein the cutter removes any material above a fixed distance below the predetermined height.

Yet another embodiment is provided in a gimbal for attaching an implement to a three-point hitch. The gimbal includes a tow plate comprising a first side and a second side wherein the tow plate comprises lower brackets on the first side arranged to connect to lift arms of the three point hitch and an upper bracket on the first side arranged to connect to a stabilizer arm of the three point hitch. An implement plate is rotationally attached to the tow plate wherein the implement plate comprises an upper implement bracket for coupling to an upper implement arm and a lower implement bracket for coupling to a lower implement arm.

Yet another embodiment is provided in a rotational cutter. The rotational cutter comprises a cutter head shaft and a multiplicity of removable cutters arranged on the cutter head shaft wherein each cutter has a cutter bracket comprising an inner void for receiving the cutter head shaft. A cutter tooth is mounted on the cutter bracket.

Yet another embodiment is provided in a turfplaner system. The turf planer system includes a tow vehicle with a three-point hitch wherein the three-point hitch has lift arms and a stabilizer arm. A gimble is attached to the three-point hitch wherein the gimble has a tow plate with a first side and a second side wherein the tow plate comprises lower brackets connectable to the lift arms and an upper bracket on the first side connectable to the stabilizer. An implement plate is rotationally attached to the tow plate. A turfplaner is attached to the implement plate wherein said turfplaner has a rotational elongated cutter comprising a first side and a second side; and a control mechanism capable of independently altering a height of the first side of the rotational cutter and the second side of the rotational cutter relative to a predetermined height over the area.

BRIEF DESCRIPTIONS OF FIGURES

FIG. 1 is a top view of an embodiment of the turfplaner.

FIG. 2 is a right hand side view of an embodiment of the turfplaner.

FIG. 3 is a left hand side view of an embodiment of the turfplaner.

FIG. 4 is a front view of an embodiment of the turfplaner.

FIG. 5 is a rear view of an embodiment of the turfplaner.

FIG. 6 is a partial cut-away view of the left hand side of an embodiment of the turfplaner.

FIG. 7 is a perspective view of an embodiment of the cutter assembly in isolation.

FIG. 7A is an exploded view of an embodiment of the cutter of the turfplaner.

FIG. 8 is a partial expanded view of an embodiment of the cutter of the turfplaner.

FIG. 9 is a perspective view of the rear roller assembly of an embodiment of the turfplaner.

FIG. 10 is a perspective view of the conveyor of an embodiment of the turfplaner.

FIG. 11 is an exploded view of the gear drive assembly of an embodiment of the turfplaner.

FIG. 12 is a perspective view of an embodiment of the turfplaner.

FIG. 13 is a view of the hydraulic control system of an embodiment of the turfplaner.

FIG. 14 is a top view of an embodiment of the turfplaner.

FIG. 15 is a right side view of an embodiment of the turfplaner.

FIG. 16 is a left side view of an embodiment of the turfplaner.

FIG. 17 is a front view of an embodiment of the turfplaner.

FIG. 18 is a rear view of an embodiment of the turfplaner.

FIG. 19 is a partial cut-away view of the left hand side of an embodiment of the turfplaner.

FIG. 20 is a perspective view of the conveyor of an embodiment of the turfplaner.

FIG. 21 is an exploded view of the gear drive assembly of an embodiment of the turfplaner.

FIG. 22 is a perspective view of an embodiment of the turfplaner.

FIG. 23 is a view of the hydraulic control system of an embodiment of the turfplaner.

FIG. 24 is a view of the master control system of an embodiment of the turfplaner.

FIG. 25 is an exploded perspective view of an embodiment of the autograde of the turfplaner.

FIG. 26 is a side view of an embodiment of the autodepth control of the turfplaner.

FIG. 27 is a perspective view of an embodiment of the autodepth control of the turfplaner.

FIG. 28 is a side cross-sectional view of an embodiment of the invention.

FIG. 29 is a bottom view of an embodiment of the invention.

FIGS. 30A and 30B are front and back perspective views, respectively, of a gimbal in isolation.

FIG. 31 is a front perspective exploded view of a gimbal and implement in isolation.

FIG. 32 is a front perspective view of an embodiment of the invention.

FIGS. 33A and 33B are back and front perspective views, respectively, of an implement plate in isolation.

FIGS. 34 and 34B are front and back perspective views, respectively, of a tow plate in isolation.

FIG. 35 is a back perspective view of an embodiment of the invention.

FIG. 36 is a top perspective view of an embodiment of the invention.

FIG. 37 is a top view of an embodiment of the invention.

FIG. 38 is a side view of an embodiment of the invention.

DETAILED DESCRIPTION

The present invention is directed to an improved attachment of an implement, particularly a turfplaner, to a tow vehicle. More specifically, the present invention is related to an improved gimbal for attachment of an implement, such as a turfplaner, to a three-point hitch of a tow vehicle.

The invention will be described with reference to the figures forming an integral non-limiting part of the present invention. Throughout the description similar elements will be numbered accordingly.

As will be realized from the figures and description herein the turfplaner is intended for use behind a pull or tow vehicle and most preferably behind a tractor. While not limited thereto, the turfplaner preferably derives power from a Power Take Off (PTO) on a tractor and from the tractor hydraulics. Other embodiments, such as a motor mounted on the turfplaner, are within the scope of the invention but a PTO drive is preferred due to cost and maintenance considerations.

The system comprises a laser which provides a planar fan beam. The turfplaner comprises an elongated cutter which removes material. Laser receivers on either side of the cutter detect whether the cutter is parallel to the fan beam or the correct distance below the fan beam. A rear transport mechanism rides on previously smoothed soil and provides a base. Hydraulic actuators raise, or lower, the blade on each end relative to the base to maintain planarity between the laser receivers and the fan beam at the proper height.

A particularly preferred embodiment of the turfplaner is illustrated and will be described with reference to the figures. The turfplaner comprises a generally rectangular frame comprising a left hand side frame, 1, and a right hand side frame, 2, with frame supports, 3-5, and a front roller, 33, spanning there between. A frame tongue, 6, and associated brace, 7, allow the turfplaner to be towed by a tractor or related tow equipment. A jack, 114, and coupler hitch, 115, are preferably provided as would be realized.

A drive assembly is illustrated in isolated view in FIGS. 11 and 21 and will be described with reference to FIGS. 11, 12, 14, 21 and 22. A gear box, 109, is mounted on the frame. The gear box can be mounted on a gear box mounting plate, 8, for convenience. The gear box couples to the PTO of a tractor through a drive shaft, 110. The drive shaft is preferably coupled through universals on either side thereof as would be well known to those of skill in the art. A cover, 125, for the drive shaft and universal joints is preferred for safety and aesthetics. Half shafts, 112, are coupled to the gear box, 109, by half shaft couplers, 111, and associated fasteners, 113. Each half shaft is preferably supported by a half shaft bearing, 96. The half shaft is coupled to a half shaft drive sprocket, 100. A half shaft cover, 25, with half shaft coupler cover, 26, are provided for safety and aesthetics. A hydraulic hose support, 94, secures the hydraulic hose extending between the tractor and turfplaner from becoming entangled with other elements. Alternatively, a drive belt, 150, can be employed with associated pulleys, 151 and 152, tensioning rollers, 105, and bushings, 153.

The half shaft drive sprocket, 100, is coupled with a cutter head drive sprocket, 101. A drive idler sprocket, 104, is preferably provided to facilitate installation tightening of a chain around the sprockets as would be realized in the art. The chain is not shown for clarity. Belts with associated pulleys and tensioning rollers can be used instead of a chain assembly. A preferred chain guard, 23, covers the chain and sprockets for safety and aesthetics. A single shaft could be employed but half shafts are preferred to minimize torque.

The cutter assembly will be described with particular reference to FIGS. 7, 7A and 8. The cutter assembly is attached to the frame. The cutting is accomplished by cutter teeth, 83. The cutter teeth are mounted on a cutter bracket, 80, with a cutter tooth mount, 82, preferably there between. The cutter bracket comprises an inner void for receiving a cutter bushing, 81. The cutter bushing is keyed the purpose of which will be more clear from further discussion. The inner voids of a series of cutter bushings are aligned and a cutter head shaft, 84, is received in the aligned inner voids. A cutter head keyway, 85, is received by the aligned key holes of the bushings. A cutter head nut, 86, on either end of the cutter head shaft secures the aligned and assembled cutters. The outer extent of the shaft is received by a cutter head bearing, 95, which is mounted to the side frames 1 and 2. As would be realized, the cutter rotation is preferably directly coupled to the PTO of the tractor through the gearing elements illustrated and described herein.

The cutters are preferably arranged in a helical fashion around the cutter head shaft. This provides an optimum cutting operation. It is preferred that the cutter rotate such that the cutter approaches the turf moving towards the direction of travel. In the present illustrations the cutter shaft would rotate clockwise as viewed from the left-hand side of FIG. 6. This direction of rotation is desirable for several reasons. One reason is an improved cut. Another reason is that the material removed by the cut is transported by the cutters and deposited on a conveyor which will be described further herein. Material is prohibited from falling to the front of the cutter by a front cutting head cover, 15, and associated brace, 21.

The conveyor assembly will be described with particular reference to FIGS. 1, 10, 17 and 20. The conveyor assembly is illustrated in isolation in FIGS. 10 and 20 and some of the belts are removed for clarity in FIG. 20. The conveyor comprises multiple continuous conveyor belts. For the purposes of the instant discussion the conveyor is described as being in three discrete units even though components could be combined or additional conveyor components added. The three components are referred to as the primary conveyor, which removes material from the interior of the turfplaner, an elevator conveyor which raises the material to a height sufficient to be dumped into a support vehicle, and an extension conveyor, which allows the tow vehicle to move beside the turfplaner at a safe distance. A primary conveyor belt, 77, preferably just behind the cutting assembly, transits material from the interior of the device and deposits the material on a conveyor elevator belt, 78, which then transports the material and deposits material on a conveyor extension belt, 79, wherein it is transported to a terminal area wherein it is preferably received by a support vehicle. A conveyor frame, (see FIG. 6), provides a support structure for the primary conveyor assembly with rollers, 12 and 69, there between. Primary conveyor belt, 77, is supported on one end by a conveyor idler roller, 72, which rides in a conveyor hanger bearing, 99, and on the other end by a conveyor drive roller (not visible) which is driven by a conveyor hydraulic motor, 89. In another embodiment the conveyors would be driven by coupling to the PTO through a gear and chain assembly or the like. The conveyor hanger bearing is attached to the frame by a conveyer hanger bearing rod, 74, which allows adjustment of the idler roller to insure the belt does not wander perpendicular to the idler roller during use. Opposite the conveyor idler roller, 72, the conveyor belt, 77, is supported and driven by a drive roller which is mounted in conveyor bearings, 98, and activated by a conveyor hydraulic motor, 89. Alternatively, a drive belt, 150, can be employed as illustrated in FIG. 17. A conveyor elevator cylinder bracket, 106, is illustrated in FIG. 20 which would be the point of attachment of a conveyor elevator cylinder (290 in FIG. 14). The conveyor belt is supported by a conventional conveyor bed plate (not shown). The conveyor bearings, 98, are secured to conveyer sides, 13 and 14. A conveyor deflector, 11, and rear conveyor cover, 16, insure that the material removed by the cutters remains on the conveyor belt. A conveyor cover, 18, with a handle, 19, for manipulating the cover is provided to prohibit material from leaving the conveyor and for aesthetics. An optional conveyor cover support angle, 17, is illustrated in FIG. 19.

The conveyor elevator transports material from the primary conveyor to the conveyor extension. The conveyor elevator comprises a conveyor elevator frame, 54 (see FIG. 12), and a conveyor elevator bed, 56, which supports the conveyor elevator belt, 77. The conveyor elevator has sides, 57, and a belt guard, 58, for safety and to prohibit material from falling from the belt. The conveyor elevator frame is mounted by a conveyor elevator pivot bracket, 59, which is attached to conveyor mounting plates, 29. The conveyor elevator belt is strung on a conveyor elevator idler roller, 73, which is attached by a conveyor elevator hanger bearing rod, 67, and aligned by a conveyor adjuster nut, 76. A second conveyor hydraulic motor, 90, provides rotational power to the elevator belt through a drive roller, 65. The conveyor hydraulic motor, 90, may be attached through a coupler as illustrated at 107 of FIG. 19. In one embodiment a single hydraulic motor can be employed yet two are preferred for enhanced control.

The conveyor extension is mounted to the conveyor elevator at a conveyor extension pivot bracket, 60. The conveyor elevator has a conveyor extension bed, 61, for supporting the conveyor elevator belt and is bound on the sides by conveyor extension sides, 62. Conveyor extension supports, 63, are preferably provided if necessary, all supported by a conveyor extension frame, 55 (see FIG. 2). A conveyor elevator spacer, 68, is provided if necessary to avoid insufficient clearance between components and, particularly, between belts rotating in non-synchronized fashion.

A transport assembly is provided, preferably, at the rear of the turfplaner. The transport assembly comprises wheels for inoperative transport and a roller which is operational during planing. The transport assembly will be described with particular reference to FIGS. 1-3, 5, 6, 9 and 12. The transport assembly comprises a roller frame top, 34, and roller frame sides, 35, generally in the form of an inverted “U” which, taken together, comprise the main frame. A cylinder roller bracket, 36, is mounted on the roller frame top. A transport hydraulic cylinder, 50, connects the cylinder bracket roller frame, 36, to a roller tankhead, 52, which functions to lower and raise the roller pipe, 51, into and out of engagement with the ground. The roller pipe, 51, is mounted on a roller shaft, 53, which is attached on either end to the roller tankhead, 52. A roller suspension frame mount, 37, on either side attached to the roller frame side, 36, connects the lower extent of the transport assembly to the frame sides, 2 and 3, through upper and lower suspension links, 42, via a suspension link tie rod, 40. A suspension sway link, 41, is preferably provided to mitigate improper tracking. Transport wheels and tires, 49, are attached to the roller frame sides, 35, through a transport leg, 44, which receives an axle. The wheel is attached to the axle by a transport spindle and hub, 48. The transport leg is attached by a transport pivot pin, 45, at a transport pivot bracket, 43, on the roller frame side. A transport hydraulic cylinder, 50, spanning between a transport cylinder top bracket, 46, on the frame and a transport cylinder bottom bracket, 47, on the transport leg, 44, rotates the wheel into and out of engagement with the ground. A roller scraper, 38, removes any material adhering to the scraper thereby providing a continuous smooth scraper surface. The roller scraper is preferably attached to the roller tankhead, 52, by roller scraper mounts, 38. During use the roller is in engagement with the ground and functions to smooth any undulations remaining from the cutter. During transport the roller is not engaged and the turfplaner is transported on the wheels.

A particular feature of the instant invention is the laser guidance system which is coupled with the hydraulics to maintain the cutter of the turfplaner in a perfectly level orientation relative to the laser beam. In prior art methods the leveling is typically dictated by a monitor based on gravity, such as a bubble level, on the machine. Each pass is therefore uncorrelated to the previous pass with regards to depth of cut. With the present invention a laser with a planar light is set up preferably beyond the location being leveled. Sensors on the turfplaner detect if they are above or below the planar light and adjust the cutter accordingly during use. Therefore, the cutter is maintained in a level orientation and each pass across an area is correlated in identical fashion to the laser. The result is a finished area which is nearly perfectly level relative to the laser after a single pass. Furthermore, the direction of travel is not relevant. Regardless of where the turfplaner is located the cutter can be maintained in a level orientation relative to the planar fan beam as long as the planar laser light can be received.

Laser proportional receivers, 118, are slidably attached to a laser mast, 32, which is attached to the turfplaner frame by a laser mast mount, 30. The laser mast mount is attached to the turfplaner to move in concert with the cutter as would be realized from the description herein. A laser control, 116, is preferably situated in a convenient location such that the laser proportional receivers can receive the beam from the laser control over the entire area being planed. The laser proportional receivers are then slid on the laser mast and fixed. The distance between the laser proportional receiver and cutter is therefore fixed and the height of the cutter is adjusted to maintain the laser proportional receiver at the same level as the laser control.

The cutter, transport assembly, and conveyors are preferably all controlled by a common hydraulic system which is illustrated in isolation in FIGS. 13 and 23. Laser hydraulic proportional valves, 117, react in a subservient manner to a laser electric solenoid, 120, to control the height of the cutting head. The hydraulic system for the turfplaner is preferably subservient to the hydraulic system of the tractor and supplied through hydraulic hoses, 92, with appropriate junctions, 93, attached to the tractor hydraulic system through standard tractor hydraulic connectors, 121. The conveyors are manipulated by the conveyor hydraulic motor, 89, and conveyor elevator hydraulic motor, 90. The machine control hydraulic cylinders, 87, attached to a bracket, 22, control the height of the cutter relative to the roller pipe, 51, with a hydraulic counterbalance valve, 88, located in each circuit for control purposes as would be readily understood. The transport assembly is manipulated by the transport hydraulic cylinder, 50, conveyor hydraulic motor, 89, and conveyor elevator hydraulic motor, 90. A hydraulic triple control valve, 91, can be used to control conveyor lift hydraulic cylinders, 290. The hydraulics can be controlled manually by a manual valve control or the hydraulics could be computer controlled.

In some instances absolute planarity is not desired but, instead, the desire is to conform an adjacent area to existing structure such as a sidewalk, drive surface, curb, aesthetic surface or the like. For example, in the case of a sports field within a track it is highly desirable to provide an autograding device to avoid any deviation from the level of the track and the playing surface adjacent thereto. It would be most desirable to have the first pass of the turfplaner match the level of the track at the interface with the track and have a smooth transition from the interface to the side of the turfplaner furthest from the track. A path the width of the turfplaner would therefore represent a slope, relative to a perpendicular to the track, which is predetermined. The side of the turfplaner opposite the track may be controlled by a laser, as described above, or an autodepth device may be employed, as will be more fully described herein. In subsequent passes the autograding can be used to match the contour of a previous pass and the other side of the turfplaner can be controlled by a laser or an autodepth device.

An embodiment of the turfplaner is illustrated in top view in FIG. 14, in side view in FIGS. 15 and 16, in front view in FIG. 17 and rear view in FIG. 18. A conveyor lift hydraulic cylinder, 290, provides for hydraulic lifting of the conveyor. A slope/cone laser, 122, and preferred tripod, 123, provide a planar laser signal which is received by the laser proportional receiver(s), 118, when lasers are used. A turfplaner controller, 119, controls the device by monitoring a combination of laser proportional receivers, autograde sensors and autodepth sensors with appropriate signal to the hydraulics to maintain the turfplaner at the proper level on each side. A 3-point hitch adapter, 140, allows the device to be easily integrated with the typical three-point hitch system of a tractor preferably with a gimbal as will be described further herein. The autograde device, 130, and autodepth device, 131, will be described in more detail below.

An embodiment of the turfplaner controller, 119, is illustrated in isolated view in FIG. 24. In FIG. 24, the turfplaner controller has a power cable, 126, for providing power to the controller. A sensor cable, 127, receives signals from the various sensors. Cables 128 and 129 are interface cables with one interface to the laser control and one interface to the control valves of the hydraulic cylinders.

An embodiment of the autograde device is illustrated in perspective exploded view in FIG. 25. An autograde mounting bracket, 138, affixes the autograde device to the turfplaner preferably in a position to be near the edge of the most outbound cutter on the side opposite the conveyor. The autograde skid, 134, rides along existing structure the contour of which is to be mimicked by the adjacent surface being planed. The length of the autograde skid is chosen to be sufficiently long to traverse minor alterations, such as expansion joints, without alteration yet not so long as to traverse intentional contours. It is preferable that the autograde skid be at least about 15 cm (about 6 inches) to no more than about 61 cm (about 24 inches). Below about 15 cm minor undulations such as expansion joints or variations in the height of adjacent bricks may be realized. Above about 61 cm aesthetic contours may be artificially truncated. The autograde skid preferably has upturned ends to insure that the skid rides on the surface. The autograde skid is mounted to an autograde link, 133, preferably with a pivot mount such as mating threaded members, 160, or the like. The autograde link is attached to, or integral to, an autograde cam, 132, which upon rotation activates at least one autograde microswitch, 135. The autograde microswitch relays alterations in contour to the turfplaner controller, 119, which activates the appropriate hydraulics to maintain the cutting head at the proper height. In the illustrated embodiment the autograde link is attached to the autograde cam by threaded members and associated washers as would be readily understood, however, any method of coupling movement of the autograde skid to a sensor would be considered within the scope of the invention.

An embodiment of the autodepth device is illustrated in side view in FIG. 26 and perspective view in FIG. 27. An autodepth adjuster, 136, fixes the desired height difference between itself and an autodepth bracket, 139, which is attached to a portion of the turfplaner which moves in concert with the roller pipe (52 of FIG. 15). As the autodepth bracket moves up and down relative to the autodepth adjuster, 136, an autodepth cam, 132, interacts with autodepth micro switches, 135. The autodepth micro switches send a signal to the turfplaner control which activates the appropriate hydraulics thereby returning the height of the cutter to the appropriate level.

An embodiment of the invention is illustrated in partial cross-sectional side view in FIG. 28, in bottom view in FIG. 29, in perspective view in FIG. 32 and in rear view in FIG. 35 attached to a three point hitch of a tow vehicle wherein the tow vehicle is illustrated in partial view for simplicity. In FIGS. 28 and 29 an implement, 200, represented as a turf planer is attached to a gimbal, 201, comprising an implement plate, 206, and a tow plate, 208, both of which will be more fully described herein. A top implement arm, 204, and bottom implement arm, 202, are attached to the implement plate and move in concert therewith. The tow plate is attached to a standard three point hitch comprising lift arms, 212, and a stabilizer arm 214, which are well known components in the industry. The lift arms raise and lower in response to the hydraulic, or in some cases electrical, lift system of the tow vehicle and the stabilizer spans the distance between the tow vehicle and implement to prohibit rotating as the implement is lifted.

An embodiment of the gimbal without the tow vehicle or implement is illustrated in perspective front view in FIG. 30A, perspective rear view in FIG. 30B and in exploded front view in FIG. 31. The tow plate, 208, comprises lower brackets, 210, arranged for mating with the lift arms of the tow vehicle and are typically connected with hitch pins, 216, as known in the art. An upper bracket, 211, is arranged to mate with the stabilizer arm, 214, as known in the art typically with a hitch pin, 216. The lower brackets and upper bracket are arranged in a triangle and rotationally fixed relative to the tow vehicle. The implement plate, 206, comprises through slots, 218. The implement plate is sandwiched between the tow plate, 208, and pivot bosses, 220, with threaded members, 222, passing through the through slots and engaging with mating threaded voids in the tow plate thereby allowing the implement plate to rotate relative to the tow plate as the threaded members slide in the though slots. The pivot bosses limit the arc of rotation of the implement plate relative to the tow plate. In one embodiment the range of the threaded members movement in the slot defines the maximum rotation arc.

A pivot lock cylinder, 224, is attached to a cylinder pivot mount, 225, on the implement plate and preferably a threaded member. The pivot lock cylinder can be a passive cylinder, such as a hydraulic cylinder, which restricts rotation but which does not otherwise force rotation in one direction or the other. The length of the throw of the pivot lock cylinder is preferably sufficiently long to restrict rotation over the entire arc of rotation allowed by the pivot bosses. Alternatively, the pivot lock cylinder can be an active cylinder which can persuade rotation in one direction or the other, such as by hydraulic force, or can be released thereby allowing free rotation within the range defined by the pivot bosses. The pivot lock cylinder and rotation bosses, taken together provide a pivot restraint capable of restricting, preferably reversibly, the arc of rotation and the rotational freedom from free rotate, when the pivot restraint is released, to persuaded rotation, when the pivot restraint is active, or to no or restricted rotation which is typically for transport. The rotation bosses are referred to herein as an arc restraint and the pivot lock cylinder is referred to herein as a free pivot restraint. In use, it is often desirable for the rotation to be relatively free while in transport it is often desirable for the rotation to be restricted.

An upper implement bracket, 226, couples with the top implement arm, 204, preferably with a primary pin, 228, passing through matching voids. Similarly, a lower implement bracket, 230, is coupled to the bottom implement arm, 202. A secondary hitch pin, 232, can be installed for transport to inhibit rotation on the axis defined by the primary pin. The secondary hitch pin is received by aligned voids or by a void and aligned slot. A swing lock cylinder, 234, preferably spanning between a lock cylinder mount, 235, and a location on the implement such as the top or bottom implement arm, inhibits swing on the axis defined by the pivot at the upper implement bracket primary pin and therefore functions as a swing restraint. The swing lock cylinder can be a passive cylinder, such as a hydraulic cylinder, which restricts swinging but which does not otherwise force swinging in one direction or the other. Alternatively, the swing lock cylinder can be an active cylinder. The swing lock cylinder preferably allows the tow vehicle to turn, with a pivot joint defined at the upper implement bracket primary pin yet during operation the swing lock cylinder restricts swinging sideways. In one embodiment the swing lock cylinder can be disengaged for turning and either fixed, or resistive, while the implement is in a work mode.

The implement, 246, attached to the gimbal can be used for any application wherein it is desirable to decouple rotation of the implement on the aid of travel with that of the tow vehicle. Other implements could benefit from the gimbal such as a turfplaner, a mower, a grader, a snow blower, a trailer, a rake, a landscaping box, a broom, a brush, a scrape blade, a plow, a turf float, a sub-soiler, and the like.

The PTO drive shaft, 248, preferably passes through central voids in the gimbal thereby allowing for a direct connection between the power take off shaft of the tow vehicle and the power head of the implement.

An embodiment of the invention is illustrated in rear perspective view in FIG. 36, in top view in FIG. 37 and in side view in FIG. 38 wherein the gimbal, 201 is attached to an implement, 200, represented as a turffloat.

The embodiment illustrated has a conveyor which is in a fixed orientation relative to the direction of travel for the turfplaner. Other embodiments are envisioned with the conveyor being capable of discharging from either side, the front or the back. A conveyor which rotates relative to the direction of travel is considered within the scope of the invention yet this is less desirable due to cost considerations. It is most preferable that the direction of travel be such that the conveyor discharges away from previously planed areas. This arrangement is preferable since it is desirable to avoid spillage of discharged material onto previously planed areas and it is desirable to not have transport vehicles on previously planed areas. It is most preferred that the autograde device be on the side opposite the conveyor since the grade being mimicked is typically an aesthetically pleasing or functional area and it is therefore desirable to avoid spillage and traffic thereon. Though an autograde device could be on both sides this is undesirable since the redundant devices increase cost and are typically not necessary. Similarly, the autodepth device is preferably on the side of the conveyor. Though an autodepth device could be on both sides this is undesirable since the redundant devices increase cost and are typically not necessary.

The instant invention provides significant flexibility. The depth or height of the cut on either side is independent of the other and the cut is independent of the movement of the tow vehicle as it transits pre-planed turf. One side can be controlled by an autograde device or a laser and the other side can be controlled by an autodepth device or a laser. Each pass of the machine across an area can be accomplished using different combinations of laser, autodepth and autograde to provide an area which is contoured to a specified predetermined shape. As would be realized the cutting height can be manipulated by manual control if desired.

Various components of the turfplaner are illustrated which are not specifically recited herein. Specifically, various covers, brackets, bushings, spacers, supports, etc. which would be included for structural strength, aesthetics to avoid contact between various components or as safety barriers are not specifically called out but are set forth in the figures and would be readily understood to be a design choice by one of skill in the art.

The instant invention is particularly suitable for any application wherein the planarity of an area is of utmost concern. The present invention can also be used to crown, or slope, areas with great precision by setting the two laser proportional receivers at different heights representative of the desired slope there between or through the use of the autograde or autodepth devices. Alternatively, each laser proportional receiver can be the same distance from the cutter and the laser fan can be tilted relative to gravity to provide a predetermined slope.

The present invention eliminates multiple passes to level an area or to make the area coplanar with an adjacent area. In practice, the invention can provide a surface which is level within 1/16 of an inch. This is previously unobtainable with prior art technologies, especially, in a single pass.

A particular application is in weed control. Some grasses, such as Bermuda grass, have a root system which is well below the surface of the ground. Therefore, the current invention can be used to scalp the surface down to a level which is above the root system of the grass or similar vegetation. Any weed, or unwanted vegetation, which has a shallow root system will be removed and the grass will quickly rise from the roots up through the surface. This provides a system for removing weeds and unwanted vegetation without chemicals. Furthermore, the area can be leveled and deweeded in a single pass.

The invention has been described with particular reference to the preferred embodiments without limit thereto. One of skill in the art would readily realize additional embodiments, alterations and improvements which are not specifically enumerated herein but which are within the scope of the invention as specifically set forth in the claims appended hereto. 

The invention claimed is:
 1. A gimbal for attaching an implement to a three-point hitch comprising: a tow plate comprising a first side and a second side wherein said tow plate comprises lower brackets on said first side arranged to connect to lift arms of said three point hitch and an upper bracket on said first side arranged to connect to a stabilizer arm of said three point hitch; an implement plate rotationally attached to said tow plate wherein said implement plate comprises an upper implement bracket for coupling to an upper implement arm and a lower bracket for coupling to a lower implement arm; and a pivot restraint comprising a pivot arc restraint wherein said pivot arc restraint comprises at least one pivot boss wherein said implement plate is sandwiched between said at least one pivot boss and said tow plate and further comprising threaded members connecting said at least one pivot boss to said tow plate through at least one slot in said implement plate.
 2. The gimbal for attaching an implement to a three-point hitch of claim 1 comprising a maximum rotation arc.
 3. The gimbal for attaching an implement to a three-point hitch of claim 2 wherein said maximum rotation arc is defined by a limit of movement of said threaded member in said slot.
 4. The gimbal for attaching an implement to a three-point hitch of claim 1 wherein said implement is said a turfplaner.
 5. The gimbal for attaching an implement to a three-point hitch of claim 1 wherein said implement is a turfplaner and said turfplaner comprises at least one of an autograde device or an autodepth device.
 6. The gimbal for attaching an implement to a three-point hitch of claim 1 wherein said gimbal further comprises a central void for receiving a PTO shaft of a tow vehicle.
 7. The gimbal for attaching an implement to a three-point hitch of claim 1 wherein said pivot restraint further comprises a free pivot restraint.
 8. The gimbal for attaching an implement to a three-point hitch of claim 7 wherein said free pivot restraint comprises a pivot lock cylinder.
 9. The gimbal for attaching an implement to a three-point hitch of claim 8 wherein said pivot lock cylinder is selected from a passive cylinder and an active cylinder.
 10. The gimbal for attaching an implement to a three-point hitch of claim 1 further comprising a swing restraint.
 11. The gimbal for attaching an implement to a three-point hitch of claim 10 wherein said swing restraint comprises a swing lock cylinder.
 12. The gimbal for attaching an implement to a three-point hitch of claim 11 wherein said swing lock cylinder is selected from a passive cylinder and an active cylinder.
 13. The gimbal for attaching an implement to a three-point hitch of claim 10 wherein said swing restraint spans between said gimbal and said implement. 